In this field it is known to use support heads provided with a base which is fixed, in use, to a support structure, for example a tripod, with a platform fixed rotatably to the base about at least one axis of rotation, and with a plate, movable with respect to the platform, to which the video-photographic apparatuses are removably attached.
To this end, the plate is provided with attaching means, mostly screw-type, by means of which the apparatus is attached to the plate.
One problem connected to the use of such heads is that of the correct positioning of the apparatus on the head.
The apparatuses, especially videographic apparatuses, are positioned on the head and then moved during use in order to take the shots.
The apparatus/head/tripod assembly must be stable, so as to avoid the operator having to support it, while taking the shots, in order to prevent it from rocking or tipping.
This involves considerable inconvenience for the operator, besides having a negative effect on the quality of the shots taken.
Customarily, before use, the apparatus is attached, via the attaching means, to the plate, and the latter is positioned along the platform in a position in which the aforesaid assembly is stable.
After use, it is necessary to separate the apparatus, head and tripod to place them in suitable containers in order to render their transport easier.
Since it is not possible to attach/detach the apparatus from the plate without removing it from the head, the apparatus is kept attached to the plate and the latter is separated from the platform after use. Therefore, for subsequent use, the positioning operation described above must be repeated, that is, the operator must position the plate bearing the apparatus on the platform and move it to a position in which the apparatus/head/support assembly is balanced.
This involves a considerable loss of time on the part of the operator, as well as inaccuracies of positioning because of the short time available for positioning.
At present, in order to facilitate the positioning operation, provision is therefore made to mark manually on the platform, for example with a pencil, or with adhesive strips, the desired position for the plate.
However, such an expedient is not easy, and so much the less secure, inasmuch as the signs can be erased, losing the marked position, or the marks made might not be correctly distinguishable.